Letter is the ninth episode of the Salad Fingers series.
Salad Fingers receives a letter from the great war.
He is experiencing some physical pain, and he "gives birth" to an organ. He thinks that the organ (really a large, slightly liquidy black mass) is a baby. He makes up his mind that his "child" is a girl that he affectionately names Yvonne.
Within a few days, Salad Fingers still looks very sick. He makes up his mind that he cannot provide the care that Yvonne needs, and takes her to the Yellow Child's house. He affectionately calls the yellow child Auntie Bainbridge, and says to Yvonne that Auntie Bainbridge will take care of her.
Before handing her over, however, Salad Fingers says goodbye and is offered a sandwich. In addition to eating the sandwich, he seems to forget that Yvonne is his child, and uses her as a wash rag to wipe the Yellow Child's windows. This turns the windows black. The episode ends here.
It is possible that Salad Fingers did not "forget" that Yvonne was his child, but instead had to abruptly end his fantasy when the yellow child wouldn't act the way "Aunty Bainbridge" would have. It appears that he had to clumsily construct a new delusion on the spot. His line "don't qualm mind, i'll chuck you this'n for nowt (nothing)" might be one part of his pysche telling himself to go along with the new fantasy. During the transition from one fantasy to the next, he stares at the black object intensely for a few seconds. Given the abrupt change in his facial expression during this time, it may be that Salad Fingers is confused as to the signifiance of this object that he now thinks is a washcloth, and begins to wipe and wash the windows of the house. Salad Fingers finishes wiping the windows and is seen eating a sandwich as the episode ends.